Metodi Ex-9

import java.util.Arrays;
import java.util.Scanner;

public class oop1 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.println("Zadachi:");
        System.out.println("1. Obrashtane na tsifrite v chislo");
        System.out.println("2. Sredno aritmetichno");
        System.out.println("3. Rezyltat ot a * x + b = 0");

        System.out.print("Izberi zadacha: ");
        int number = scanner.nextInt();
        System.out.println();

        if (number == 1){
            System.out.print("Vavedi chislo > 0: ");
            int num = scanner.nextInt();

            reversedNumber(num);
        }
        else if (number == 2){
            System.out.print("vavedete posledovatelnostta, razdelena ot \",\": ");
            String line = scanner.next();//2,5,10,5,8

            averageOfLine(line);

        }else {
            System.out.print("vavedete dvoinite promenlivi \"a\" and \"b\" (a != 0): ");
            double a = scanner.nextDouble();
            double b = scanner.nextDouble();

            printSolution(a, b);
        }
    }

    private static void printSolution(double a, double b) {
        //a * x + b = 0
        double x = -b / a;
        System.out.printf("x = %.2f", x);
    }

    private static void averageOfLine(String line) {
        int[] result = Arrays.stream(line.split(",")).mapToInt(Integer::parseInt).toArray();
        int sum = 0;
        for (int i = 0; i < result.length ; i++) {
            sum += result[i];
        }
        double average = sum * 1.0 / result.length;
        System.out.printf("%.2f%n", average);

    }

    private static void reversedNumber(int num) {
        while (num > 0) {
            int lastDigit = num % 10;
            System.out.print(lastDigit);
            num /= 10;
        }
        System.out.println();
    }
}